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(No Model.)

H. F. KNAPP.

SHORE PROTECTOR AND BEACH BUILDER.

No; 247,065. Patented Sept. 13,1881.

N. PETERS. PlwibL-hhognphqr. Washington. D C.

UNITED STATES PATENT OFFICE.

HENRY F. KNAPP, OF NEW YORK, N. Y.

SHORE-PROTECTOR AND BEACH-BUILDER.

SPECIFICATION forming part of Letters Patent No. 247,065, datedSeptember 13, 1881.

Application filed July 9, 1881. (No model.)

To all whom it may concern:

Be it known that I, HENRY F. KNAPP, of the city, county, and State ofNew York,have invented a new and useful means whereby the force ofsea-waves may be stopped from cutting into and away shores, beaches,&c., without causing any impediment to navigation, the same means alsobeing applicable to piers projecting into a sea, and will afford greaterfacility and safety for the landing and mooring of vessels alongside bylessening the undulation of the water, all of which is set forth in thefollowing specification, reference being had to the accompanyingdrawings.

All sand beaches are subject to constant change in hydrography andtopography by reason of the varying conditions of ocean currents andforce from time to time; and as many marine villas, hotel properties,and farms situatedon the ocean-front are being more or less affected andwashed away by the force of the sea-waves, the object of this inventionis to efl'ectively and economically afford the requisite protectionwithout defacing the sea-view, impeding navigation, or encroaching onthe oceans domain. This will be accomplished by building an artificialbar, submerged and about parallel with the beach, which will cut downand absorb the force of thesea-waves beating on the shores and destroy apart of their force, so that they will strike and break on the shoresafter passing the artificial bar with far less eroding, tearing, andwashing eflect. By this means a beach can be efl'ectively saved fromwashing away, while with slight modifications, according to thehydraulic conditions of the locality, the sand thrown insidethesubmerged bar by the waves may be held there to build up the beach,or the currents may be made to take away such sand.

Wave force running up an inclined beach often rapidly resolves itself inpart into a shore or tidal current (while at the same time it willmaintain its wave-like character) by reason of its excessive acquiredmotion, and which current, as well as any real shore-current that maypertain to the locality, it is intended this bar shall also impede.

In further explanation it may be stated that wave force is always usedup by friction on the bottom, and this artificial bar concentrates muchof that friction on itself.

Referring to the drawings, Figure 1 represents a top-plan view of asandy beach, A,

washed away and cut into at b by reason of the excessive force ofthewaves at this point. 0 represents the submerged bar, built of stoneor other heavy or fixed material, so as to be immovable by sea force,and quite parallel with the shore line. This bar may have right orobtuse angled extensions 0 toward the shore in case it is also desiredto reduce any shorecurreuts that may exist, whether induced by waveaction or otherwise. These extensions striking into the heart of deeperwater are far more effective than their same capacity projecting fromthe shores. This entire bar and its extensions are to be submerged sofar under the water-surface as to be invisible, as well as to permit allvessels frequenting the locality to pass safely over its. top or apex.

Fig. 2 represents a vertical section of Fig. 1, having like letters ofreference, but also showing the undulating water-surface W running uponthe shore, but not showing the inshore-bar extensions.

Fig. 3 represents apierwith the bar in front of it for its protectionand the facility of landing at it. This artificial bar, elevated severalfeet above the bottom and being parallel with the waves as they advanceonto it, will take from their force proportionately to its height abo ethe bottom, and consequently the waves. after passing it, will advanceon the shore with a much reduced force.

What I claim, and desire to secure by Letters Patent, is-

1. A submerged artificial bar, (J, built about parallel with the shore,as and for thepurpose described.

2. A submerged artificial bar, 0, having inshore-extensions C, asdescribed.

3. A submerged artificial bar, 0, acting for the protection of a pier,and for the facility of landing vessels thereat.

HENRY F. KNAPP.

Witnesses ALBERT F. CARY, E. E. FITZGERALD.

